1. Field of the Invention
The invention relates to capillary bridge viscometers useful for measuring the relative viscosity of a solute in solution with a solvent for said solute.
2. The Prior Art
A common method employed to obtain information respecting molecular weights of solvent soluble thermoplastic polymers is to measure the viscosity of dilute solutions of such polymers in a suitable solvent. From the knowledge of the viscosity of such dilute solution and the known viscosity of the solvent employed in such determinations, it is possible to obtain data respecting the relative viscosity, specific viscosity, and inherent viscosity of such thermoplastic polymers.
The usefulness of methods for determining molecular weight of polymers by this method is limited by the quantity of work and the time required to obtain such data. Such data are customarily obtained by preparing the polymer solutions and measuring the viscosity of the solutions in carefully calibrated viscometers. To obtain data respecting intrinsic viscosity, it is necessary to measure relative viscosity a several concentrations and to extrapolate such data to zero concentration of the solute in the solvent.
It would be highly desirable to have available to the art apparatus for measuring such viscosities with a high level of precision in relatively short time periods. Notwithstanding the desirability of having such apparatus, the applicant is not aware of apparatus which will measure such viscosities conveniently and accurately in short periods of time.